1. Field of the Invention
The present invention relates to a method and implement for installation of spiral hangers for hanging a cable on a messenger wire.
2. Description of Related Art
Conventionally, a hanger system 100 as shown in FIGS. 15 and 16 has been commonly used to hang a cable from a messenger wire and fix the cable thereto. The procedure for installing a cable using such a hanger system will be described with reference to FIG. 15. First, a plurality of pulleys 121 are attached to a messenger wire 102 which has been installed between electric utility poles 101a and 101b. A pull rope 122 is then passed through the pulleys 121 and is connected to a winch 103. The winch 103 is then operated so as to cause a cable 114 connected to the pull rope 122 to run between the electric utility poles 101a and 101b. Subsequently, hangers 106 shown in FIG. 14 are attached to the messenger wire 102 at intervals of 50-60 cm and the pulleys 121 are removed. These operations are performed by a worker 104 who dangles in midair between the electric utility poles 101a and 101b. This is called midair dangling work. Therefore, the worker 104 must have experience, and this work is time consuming and dangerous. Also, an accident has occurred in which a pulley 121 fell down and injured a passer-by. Accordingly, a strong desire exists to solve the above-described problems.
Also, when a cable is supported by use of hangers, there is the possibility that the hangers may fall down or slide sideways due to external causes, with the result that proper support of the cable cannot be maintained and the characteristics of the cable are adversely affected.